I need to add some validations before the user navigates away via an ASP.NET Menu.

I noticed that the items are rendered to use a javascript function called Menu_Key

<td id="ctl00_MainMenun1" onmouseover="Menu_HoverStatic(this)" onmouseout="Menu_Unhover(this)" onkeyup="Menu_Key(this)">

I there a way to override that function and have the menu execute one of mine, from which I could validate what I need and then call the original?

I need to add some validations before the user navigates away via an ASP.NET Menu.

I noticed that the items are rendered to use a javascript function called Menu_Key

<td id="ctl00_MainMenun1" onmouseover="Menu_HoverStatic(this)" onmouseout="Menu_Unhover(this)" onkeyup="Menu_Key(this)">

I there a way to override that function and have the menu execute one of mine, from which I could validate what I need and then call the original?

• asp
• javascript
• menu

5 Answers 5

Redefine the function after it was initially defined, but keep track of it in a var so that you can call it later. You would effectively be renaming the original Menu_Key function.

var originalMenu_Key = Menu_Key;

Menu_Key = function(t) { 
   // do your validations here

   if ( /* everything validated */ ) {
     originalMenu_Key (t);
   }
};

Above solution is a valid one, but in mon case redefinition can be done in a bit more flexible way

var originalMenu_Key = Menu_Key;

Menu_Key = function(t) { 
   // do your validations here

   if ( /* everything validated */ ) {
     return originalMenu_Key.apply(this,argumets);
   }
};

In such case , any changes in function signature , will not break wrapping logic.

Just redefine the function at the bottom of the page (technically after the initial declaration).

You have more than one way to do this. Depend of what you want.

If you want a function to run before the existing one then add this.

<td id="ctl00_MainMenun1" onmouseover="Menu_HoverStatic(this)" 
onmouseout="Menu_Unhover(this)" onkeyup="my_Function(); Menu_Key(this);">

If you want to run the second function conditionally then add this

<td id="ctl00_MainMenun1" onmouseover="Menu_HoverStatic(this)"
onmouseout="Menu_Unhover(this)" onkeyup="my_Function(this);">


function my_Function(sender)
{
  if(valid)
     Menu_Key(sender);
}

Use the js code:

    $(document).ready(function () {

    $("td").mouseover(function(){
          alert('MouseOver validation content goes here.');
        }).mouseout(function(){
          alert('MouseOut  validation content goes here.');
});

hth!